Apple was a bright spot in 2009 in terms of PC sales, but the signals are mixed as to whether the Mac can grow beyond its niche

It's almost a pathetic assertion: This year, the Mac will break out of its ghetto and become a mainstream computer for individuals and businesses alike. That unfulfilled desire is foretold every year and has been since the mid-1980s, when Apple's then-groundbreaking computer was quickly sidelined by the IBM PC and, later, Microsoft Windows.

The strong growth of the iPhone and the big buzz around the recently announced iPad could give the Mac an extra boost, giving happy customers reason to consider switching to a Mac for the same levels of delight, sophistication, and quality.

So will 2010 be any different? A few days before the annual Macworld Expo celebratory confab begins, it's a natural time to ask whether it is just Mac fans pining for validation who will claim that this year is the year of the Mac. Maybe, but there are signs that this time they may be right. However, there are also signs that they're wrong -- again.

Let me be clear: I've long had a love/hate relationship with Apple and the Mac. I use a Mac as my preferred PC, but only after I first tried Windows Vista. For most of the decade, I was an XP user, and in the 1990s I was bi-platform, a Macworld editor whose history had been on the PC side and who had issues with Apple's extreme arrogance (a flaw that endures undiminished today), as well as the mediocre quality of its 1990s-era Macs. But even in the dark times, I embraced the Mac's more human design quality, and when Apple resurrected itself in the 2000s, I cheered it on.

So I was happy to see that sales of Apple's pricey MacBooks grew in 2009 despite the recession. In fact, with the exception of one fiscal quarter, Apple's Mac sales have grown faster than PC sales for five consecutive years.

Yet despite new-PC sales share estimates between 6 and 12 percent, the Mac's total installed base hovers around 4 percent -- a fact that could, as AppleInsider wisely argues, be cause for optimism, indicating plenty of room for growth, or pessimism, suggesting the Mac has too small a base to gain much traction, especially in businesses where exceptions are frowned on.